This invention relates generally to preparation of anti-fouling compounds, and more particularly to an improved method for batch production of crosslinked poly(tri-n-butyltin)methacrylate.
Crosslinked poly(tri-n-butyltin)methacrylate, an organometallic polymer, hereafter referred to as OMP-5, is used as an anti-fouling agent to prevent the growth of marine organisms on the hulls of ships. The current process for preparing OMP-5 calls for esterification of crosslinked polymethacrylic acid with tributyltin oxide (TBTO) in the presence of toluene. The toluene permits azeotropic distillation of water in an effort to drive the esterification reaction between the crosslinked polymethacrylic acid and the TBTO. The resultant product has an enlarged particle size which must be mechanically ground down to a size which is more useful as a pigment in antifouling coatings. Generally, the grinding step is performed after the esterification, however, the order may sometimes be reversed.
In either case, the mechanical grinding step and the associated handling constitute a significant portion of the cost of producing OMP-5. Also, substantial material losses are often incurred in the grinding operation. Furthermore, the grinding operation generates respirable dusts which could be hazardous to the health of personnel exposed thereto.